Thiocyanate slime control composition and its use

ABSTRACT

The present invention relates to certain processes and compositions useful for inhibiting and/or controlling the growth of slime in water and, in particular, water employed for industrial purposes. Water employed in the manufacture of pulp paper and water employed in cooling water systems, as well as other industrial waters, provide environments which are conducive to slime formation. The novel compositions of the present invention are mixtures which show unexpected synergistic activity against microorganisms, including bacteria, fungi and algae, which produce slime in aqueous systems. The slime, of course, is objectionable from an operational and/or an aesthetic point of view. Specifically, the invention is directed to and the use of composition comprising a combination of 5-chloro-4-phenyl-1,2dithiole-3-one and methylene bisthiocyanate and derivatives thereof. The inventive compositions inhibit the growth of slime in water, or more specifically, possess biocidal activity against bacteria, fungi and/or algae. The derivative of the dithiole-3one and thiocyanate compounds contemplated for use in accordance with the present invention are those which possess the capacity to kill or inhibit the growth of slime-forming microorganisms such as bacteria, fungi and algae.

Unite States Swered et al.

[ THIOCYANA'TE SLIME CONTROL COMPOSITION AND ITS USE [75] Inventors: Paul Swered, Philadelphia; Bernard F. Shema, Glenside; Robert H. Brink, Jr., Doylestown, all of Pa.

[73] Assignee: Betz Laboratories, Inc., Trevose, Pa.

[22] Filed: Sept. 20, 1971 [21] Appl. N0.: 182,257

[52] U.S. Cl 424/277, 71/67, l62/l6l,

424/302 [51] Int. Cl AOln 9/02 [58] Field of Search 71/67, 90; 424/277, 302

[56] References Cited UNITED STATES PATENTS 3,031,372 4/l962 Brack 424/277 3,674,457 7/l972 Wolfson 7l/67 Primary Examiner-James 0. Thomas, Jr. Attorney, Agent, or FirmAlexander D. Ricci [57] ABSTRACT The present invention relates to certain processes and Jan. 21, 1975 able from an operational and/or an aesthetic point of view. Specifically, the invention is directed to and the use of composition comprising a combination of 5- chloro-4-phenyl-l,2-dithiole-3-one and methylene bisthiocyanate and derivatives thereof. The inventive compositions inhibit the growth of slime in water, or more specifically, possess biocidal activity against bacteria, fungi and/or algae. The derivative of the dithiole-3-one and thiocyanate compounds contemplated for use in accordance with the present invention are those which possess the capacity to kill or inhibit the growth of slime-forming microorganisms such as bacteria, fungi and algae.

10 Claims, No Drawings THIOCYANATE SLIME CONTROL COMPOSITION AND ITS us BACKGROUND OF THE INVENTION The formation of slime by microorganisms is a problem which attends many systems. For example, lagoons, lakes, ponds, pools and such systems as cooling water systems and pulp and paper mill systems all possess conditions which are conducive to the growth and ganisms in aqueous systems, such as cooling water systems and pulp and paper mill systems, and for controlling slime formation or microorganism populations in aqueous bodies in general. Moreover, another object of the invention is the provision of methods for preserving materials and forcontrolling slime-forming microorganisms in any aqueous system which is conducive to the growth and reproduction of microorganisms and, in

Aerobic and heliotropic organisms fluorish'on the tower proper while other organisms colonize and grow in such areas as the towersump and the piping and pas,- sages of the cooling system. Such slime-serves to deteriorate the tower structure in the case of wooden towers. In addition, the deposition of slime on metalsurfaces promotes, corrosion. Furthermore, slime carried through the cooling system plugs and fouls lines, valves, strainers, etc. and deposits on heat exchange surfaces. In the latter case, the impedance of heat transfer can greatly reduce the efficiency of the cooling system.

In pump and paper mill systems, slime formed by microorganisms is also frequently and, in fact, commonly encountered. Fouling or plugging by slime also occurs in the case of pulp-and paper mill systems. Of greater significance, the slime becomes entrained in the paper produced to cause breakouts on the paper machines with consequent work stoppages and the loss of production time or unsightly blemishes in the final product; this, of course, results in rejects and wasted output. The previously discussed problems have resulted in the particular, cooling water and paper and pulp mill systems. These methods employ a combination of 5- chloro-4 phenyl-l,2-dithiole 3-one and methylene bisthiocyanate or derivatives thereof. The derivatives, however, must possess the property of being biocidally active against bacteria fungi and/or algae, i.e. either kill or inhibit the growth of these microorganisms.

In the practice of the invention, the combination is added to the particular material to'be preserved or to the system being treated, forexample cooling water systems, paper and pulp mill sysems,.pools, ponds, la-

goons, lakes, etc., in a quantity adequate to control the slime-forming microorganisms which are contained by, or which may become entrained in, the system which is treated. It has been found that such compositions and methods control the growth and occurrence of such mi-- croorganisms as may populate these particular systems.

GENERAL DESCRIPTION OF THE lNENTlON As earlier stated, the inventive compositionscomprise a combination of 5-chloro-4-phenyl-l,Z-dithiole- 3-one and methylene bisthiocyanate with either compound being present in such quantity as to-impart a synextensive utilization of biocides in cooling water and pulp and paper mill systems. Materials which have enjoyed widespread use in such applications include chlorine, organo-mercurials, chlorinated phenols, organobromines, and various organo-sulfur compounds. All of these compounds are generally useful for this purpose but each is attended by a variety of impediments. For example, chlorination is limited both by its specific toxicity for slime-forming organisms at economic levels and by the ability of chlorine to react which results in the expenditure of the chlorine before its full biocidal function may be achieved. Other biocides are attended by high costs, odor problems and hazards in respect to storage, use or handling .which limit their utility. To' date, I no one compound or type of compound has achieved a clearly established predominance in respect to the applications discussed. Likewise, lagoons, ponds, lakes and even pools, either used for pleasure purposes or used for industrial purposes for the disposal and storage of industrial wastes become, during the warm weather, besieged by slime due to 'microorganism growth and reproduction. In the case of the recreational areas, the problem of infection, odor, etc. is obvious. In the case of industrial storage or disposal of industrial materials, the microorganisms cause additional problems which must be eliminated prior to the materials use or the waste is treated for disposal.

It is the object of the present invention to provide compositions for controlling slime-forming microorergistic behavior for the purpose to the composition as a whole. Preferably, the compositions contain a percentage by weight ranging from about 5 to about of the dithiole-3-one compound and from about 5 to 95% of methylene bisthiocyanate (note U.S. Patent 3,426,134). When these two ingredients are mixed either beforehand or by addition to the aqueous system individually, the resulting mixtures possess a high degree of slimicidal activity which could not have been predicted beforehand from the known activity of the individual ingredients comprising the mixture. Accordingly, it is therefore possible to produce a more effective slime-control agent than has previously been available. Because of the enhanced activity of the mixture, the total quantity of biocide required for an effective treatment may be reduced. In addition, the high degree of biocidal effectiveness which is provided by each of the ingredients may be exploited without use of the higher concentrations of each. This feature is not only important and advantageous from an economical point of view, but also most desirable from the pollution or ecological standpoints. In this regard, it might be pointed out that the smaller the amount of a chemical that'is required for effective treatment, the smaller the problem in treating thewastes from these systems. In both cooling water systems and in paper and pulp mill systems, certain discharge of waste water, eg blowdown in cooling water systems, is a necessity. However, because of the current concern and legislation regarding the discharge of wastes, the effluent waste water must be treated to reduce and, hopefully, to eliminate any undesirable constituents. This treatment, of course,

is time-consuming and costly. Accordingly, a reduction To demonstrate the synergism which is obtainable from the combination of methylene bisthiocyanate [Stauffer Chemical Co. N-948] with the 5-chloro-4- phenyl-l,2-dithiole-3-one (supplied by Hercules Cor- Poratlon under designation S4612), Various tests were 5 where just minor amounts of one or the other are presutilized and will be described following ent. This discovery of synergism at the lower levels is SPECIFIC EMBODIMENTS extremely valuable since it illustrates conclusively that EXAMPLE 1 the ingredients are compatible over the wide percentage by weight range. SYNERGISTIC COMBINATION BACTERICIDAL EFFECTIVENESS Compound A: -chloro-4-phenyl-l,2-d1th1ole-3-one The bactericidal effectiveness of the mixture of Com- Compound B: methylene bisthiocyanate i The compositions of this Example contained 5- pound A and compolmd B of l Eidmple ip chloro 4 phenyl l,z dithiole 3 one (referred to as strated by the following Table in which the inhiblting Compound A in the Test Equations and in Tables 1 power of a 50/50 by we'ght mlxture of A and B through 1C) and methylene bisthiocyanate (referred to Shown- Aerobacter aemgenes was employed as the test as Compound B in this Example and in the Test Equa organism and a substrate technique was utilized. Spetions and in Tables 1 through 1C) in the weight ratios clfically, the biocidal mixture was added in gradually expressed in the Tables which follow. The composiincreasing quantities to nutrient agar media which was tions were tested for synergistic activity in accordance then inoculated with A. aerogenes. The preparation was with the method described. The synergism test was utithen incubated for 48 hours. The values set forth in the lized t0 evaluate each Of the combinations Of this EX- Table indicate the quantity of biocide required, in parts ample by weight for each one million parts by weight of the y g i lndfix medium, in order to achieve complete inhibition of the Synergistic activity was demonstrated by adding growth of the test organist Compound A and Compound B in varying ratios and over a range of concentrations to liquid nutrient me TABLE 1A dium which was subsequently inoculated with a standard volume of suspension of the bacterium Aerobacter Quarftity (pp t v aerogenes. Following two days incubation, the lowest Biocida Material gz xl zg gll 'g concentration of each ratio which prevented growth of the bacteria was taken as the end point. Growth or no- Compound A (5%). Compound B growth was determined by turbidity or clarity respec- (5%) (90%) 60 tively in the medium. End points for the various mixtures were then com ared with end oints for the ure active ingredients wtiiking alone in c oncomitantly pre- FUNGICIDAL EFFECTIVENESS pared culture bOmeS synergism was determined by in order to test the effectiveness of the 1nvent1ve mixmethod described by Kul] ct p Kn, p tures in respect to fungi, evaluations were made followman, syiwestrowicz and L Mayer, Applied ing the procedures described by B. F. Shema and J. H. Mi bi 9 533 41 19 1)] and h l i Conkey [Journal for the Technical Association of The hi Pulp and Paper Industry, 36, 20A30A, (1953)]. The described procedure generally entails incorporating the (CPU/(O0) (ON/(Ob) 1 addmvlty biocide under test in a nutrient substrate such as agar, 1 is antagonism malt, etc. and pouring the resulting medium into a Petri 1 is synergism 45 dish and allowing the medium to solidify. A button of fungus inoculum is placed on the surface of the solidiwhere fied medium and the medium is incubated for a period Quamljty o.fnctompound A actmg alone produc' of 14 days. After the period, the diameter of the colony l g g sg compound B acting alone produo is measured and compared with the diameter of the g an end point button of inoculum originally placed upon the surface.

Qb Quantity of Compound A, in the mixture If thereis no increase in the diameter, thegrowth of the ducing an end point fungus is considered to be completely inhibited and the QB Quantity of Compound 8 in themixture treatment level which accomplished this is considered ducing an end point the inhibitory concentration. The fungal species uti- For mixtures f Compounds A and B, and f C lized as the test microorganism to evaluate the efficacy pound A and Compound B acting alone, the f ll ing of the present mixture were Penicillium expansum and results were observed: Aspergillus TABLE 1 Weight Ratio Quantities Producing End Points (ppm) (OJ/Q") (O /Oh) (Q. /Q,, 0 1/01,) of A to B Q, 0,, Mixture it is evident from the data recorded in'Tablc 1 that compositions of the present invention function to control slime growth due to microorganisms not only at equal portions of the respective ingredients, but also 5 TABLE lB Quantity (ppm) for inhibition tions or dispersions. For example, a preferred Solution .comprises between 5 to 65% by weight of the synergistic combination in admixture with various solvents and solubilizing agents. An example of such a synergistic B'wda] Mammal f Expansum 5 biocidal product comprises from about 5 to 10% by Compound A (5%), Compound B weight of the methylene bisthiocyanate, .from about 5 5%)- (90%) to 10% by weight of the -chloro-4-phenyll ,Z-dithiole- 3-one and the remainder composed of such materials SLIME CONTROL EFFECTIVENESS as surfactants, stabilizers, organic solvents,'such as al- The inventive methods and compositions were also. kanols, aromatic hydro-carbons and/0r watch tested with respect to their performance in the control surfactams'sueh as the'alkylaryl polyether alcohols of slime formation in industrial systems. In this test an pelyether alcohols lf t ahd lf t and the indusirifii recirculating Water oiitaiiied from f like, may be employed to enhance the dispersibility and tem which was curismiy expsnencmg pfobiems i stability of these dispersions, The foregoing solutions of speci to the formation of slime by microorganisms the biocidal compositions are utilized in order to insure Such tests do not demonstrate the efficiency of the biothe rapid and uniform dispersihihty of the biocides cide p y with respect to p i Species within the industrial water which is treated. it has been cfooi'gaiiisms but instead supply a Practical demonstia' found that either aqueous or non-aqueous solvents are tion of the efficacy of the biocide tested in relation to generally Suitable in the preparation f Compositions f those communities of microorganisms which have the invention, e.g., methyl cellosolve, organic solvents denced their ability to form slime in actual industrial Such as the ahphati'e and aromatic hydrocarbons, systems kerosene. Based upon the synergism study as outlined in the testing of recirculating Water P r a above, it was ascertained that in the treatment of paper smite evaluation was p -y in such testing ideiiiimill and cooling water, effective biocidal action is ob- Cai Portions of water samples are treated with varying tained when the concentration or treatment level of the Concentrations of biocide and two Portions are left combination or admixture of biocides is between 0.5 treated to serve as controls. The control portions are parts iili to 1,000 parts permillio i, d ef plated for total count at the beginning of biocidetreat- I bl between 1 d 100 parts per illi b s d upon ment and all portions are plated for total count at S e the total content of the aqueous system treated, such as suitable i p after beginning biocide treatthe total quantity of cooling water or paper mill water. ment. Using the counts obtained from the plating,.the The compositions may also be utilized for the preserpercentage kill (based on the initial control count) may vation of slurries and emulsions containing carbohybe calculated. In this evaluation the water sample was drates, proteins, fats, oils, etc.; dosage levels for this, taken from a white water system in a paper mill located purpose range in the vicinity of 0.01 to 5%. The comin the northeastern United States: positions of the invention which can be prepared by For the purposes of comparison, the mixture of A merely combining the respective ingredients and mixand B was evaluated together with two recognized ing thoroughly at standard conditions may be fed concommercial biocides, P entachlorophenol and a Comtinuously to the treated system, e.g., by means of a memercial Product. t'ered pump, or may be fed periodically at predeter- TABLE lC Quantity of Percent kill Biocidal Material hiocidc (ppm) after 3 hours Compound A (5%). Compound B (5% lncrt (90% 25 54 do. do. do, 5O 92 do. do. do. 100 99 Pentachlorophcnol 100%) 25 4 do. 26 do. 100 99 Commercial product (30% active: Combination'of dithiocarhamatcs) 25 l 1 do. 50 28 do. l()() 89 A perusal of the recorded percentages clearly estabmined intervals calculated to control the growth of lished that'the composition of the present invention, slime-forming organisms in'the system; Naturally, in although less concentrated with respect to active ingre-" the treatment of cooling water, the feeding of the indients as compared to the two commercial products, ventive compositions must be designed to compensate gave excellent rates of kill even at low temperature levfor blowdown in those systems which employ that expeels. As earlier expressed, excellent performance of a dient. biocidal composition at low treatment levels not only Al h h h f goi g h b p ifi ll i e provides a most desirable cost performance index, t to liquid formulations, the combinations of the invenalso provides most desirable advantages-from the 215- ti may, of course,be formulated dry with'well-known pects of pollution abatement, waste treatment costs ll i i m @gq di hl id talc, i iand the preservation of the ecological strain.

When the inventive compositions are employed in the treatment of cooling or paper 'mill water, they are preferably utilized in the form of relatively dilute solunate, etc. to produce solid pellets or briquettes which are added directly to the systems to be treated. The pellets or briquettes, of course, dissolve in accordance with predetermined conditionsor rates.

In describing the inventive subject matter, the expression composition" has been utilized. However, it is to be understood that physical compositions or combinations are not the sole utility of the invention. If, for example, the separate ingredients of the composition are added independently to a particular system, it is intended that this usage of the subject matter is within the scope of the invention and is to be construed within the broad interpretation of composition and/or combination.

As would be expected, the inventive composition may be added to the cooling water or paper and pulp mill systems at any convenient point. Naturally, in once-through or non-circulating system, the composition must be added upstream from the point or points at which microorganism control is desired. In circulating systems or pulp and paper systems, the compositions must be added at any point provided that the time lapse and the conditions experienced between point of addition and the point at which the effect of the composition is to be experienced are not so drastic as to result in the neutralization of the effect of the composition.

Although the invention has been described as being directed to specific compositions comprising -chloro- 4-phenyl-l,2-dithiole-3-one in combination with methylene bisthiocyanate, it is obvious that homologs, analogs, etc. of the dithiole-3-one and the thiocyanate compounds are operable for the purpose. The provision, of course, is that the derivatives possess biocidal or growth inhibitory capacities with respect to bacteria, fungi, and algae.

it should be noted that while the evidence has been derived from the treatment of samples taken from a paper and pulp mill aqueous system, the compositions and methods of the present invention are broadly applicable to the treatment of aesthetic waters as well as industrial waters, such as cooling waters, waste water, streams, lagoons, etc. which are plagued by slimeforming organisms.

Having thus described the invention, what we claim l. A method for controlling the growth of the microorganism Aerobacter aerogenes in an aqueous system in which said microorganism is found which comprises adding to said system so as to contact said microorganism an effective amount of a combination comprising 5-chloro-4-phenyl-1,2-dithiole-3-one and methylene bisthiocyanate and mixtures thereof, wherein the weight ratio of the dithiole to the bisthiocyanate is from about 5 to about to about 95 to 5%.

2. A method according to claim 1 wherein the combination contains approximately 50% by weight of each of said dithiole-3-one and said compound.

3. A method according to claim 1 wherein the combination is added to said system in any amount of from about 0.5 to about 1,000 parts by weight of said composition per parts by weight of said aqueous system.

4. A method according to claim 3 wherein the composition is added to said system in an amount of l to parts per million parts of said aqueous system.

5. A method according to claim 3 wherein the aqueous system is the aqueous system of a cooling water system.

6. A method according to claim 3 wherein the system is the aqueous system of a pulp and paper mill system.

7. A method of preserving materials which are subject to attack by the microorganism Aerobacter aerogenes which comprises incorporating in said material containing an amount of said microorganism from about 0.5 to 5% by weight of a combination comprising 5-chloro-4-phenyl-l,2-dithiole-3-one and methylene bisthiocyanate and mixtures thereof, wherein the weight ratio of the dithiole to the bisthiocyanate is from about 5 to about 95% to about 95 to about 5%.

8. A composition which is effective in controlling the growth of the microorganism Aerobacter aerogenes in an aqueous system in which said microorganism is found comprising 5-chloro-4-phenyl-l ,2-dithiole-3-one and methylene bisthiocyanate and mixtures thereof, wherein the weight ratio of the dithiole to the bisthiocyanate is from about 5 to about 95% to about 95 to 5%.

9. A composition according to claim 8 wherein the composition contains approximately 50% by weight of each of said dithiole-3-one and said compound.

10. A biocidal product which is effective in controlling the growth of the microorganism Aerobacter aerogenes in an aqueous system in which said microorganism is found comprising from about 5 to 10% by weight of 5-chloro-4-phenyl-l,2-dithiole-3-one and from about 5 to 10% by weight of methylene bisthiocyanate and mixtures thereof, and the remainder composed of a material selected from the group consisting of surfactants, stabilizers, organic and inorganic solvents and 

2. A method according to claim 1 wherein the combination contains approximately 50% by weight of each of said dithiole-3-one and said compound.
 3. A method according to claim 1 wherein the combination is added to said system in any amount of from about 0.5 to about 1, 000 parts by weight of said composition per parts by weight of said aqueous system.
 4. A method according to claim 3 wherein the composition is added to said system in an amount of 1 to 100 parts per million parts of said aqueous system.
 5. A method according to claim 3 wherein the aqueous system is the aqueous System of a cooling water system.
 6. A method according to claim 3 wherein the system is the aqueous system of a pulp and paper mill system.
 7. A method of preserving materials which are subject to attack by the microorganism Aerobacter aerogenes which comprises incorporating in said material containing an amount of said microorganism from about 0.5 to 5% by weight of a combination comprising 5-chloro-4-phenyl-1,2-dithiole-3-one and methylene bisthiocyanate and mixtures thereof, wherein the weight ratio of the dithiole to the bisthiocyanate is from about 5 to about 95% to about 95 to about 5%.
 8. A composition which is effective in controlling the growth of the microorganism Aerobacter aerogenes in an aqueous system in which said microorganism is found comprising 5-chloro-4-phenyl-1, 2-dithiole-3-one and methylene bisthiocyanate and mixtures thereof, wherein the weight ratio of the dithiole to the bisthiocyanate is from about 5 to about 95% to about 95 to 5%.
 9. A composition according to claim 8 wherein the composition contains approximately 50% by weight of each of said dithiole-3-one and said compound.
 10. A biocidal product which is effective in controlling the growth of the microorganism Aerobacter aerogenes in an aqueous system in which said microorganism is found comprising from about 5 to 10% by weight of 5-chloro-4-phenyl-1,2-dithiole-3-one and from about 5 to 10% by weight of methylene bisthiocyanate and mixtures thereof, and the remainder composed of a material selected from the group consisting of surfactants, stabilizers, organic and inorganic solvents and mixtures thereof. 